Here's what I ended up installing a few weeks ago... My solenoid crapped out a while back, so I just removed that component and the wires connecting it to the starter. Some people go as far as to remove the sprag from inside the primary case, and sometimes the inner workings of the starter, although I think you need to keep the starter's housing since there isn't a readily available part to close off the gaping hole it would leave in the front of your engine.

Battery I bought... 1000 miles on it and it's working great. This battery is so small that I imagine anything would work on a kick-only machine:

It's basically a tiny dirt bike battery. Some guys on a triumph forum say it works great for their older kick-only 650's. This particular model is great because it's only 1.5 inches thick so i can tuck it up under the seat, and the best part, you can find it for $20 including shipping. Added to that, it's an AGM battery so I can use my battery tender that I already have, and don't need to invest in a high tech charging system.It's only 2.5 AH but heck, it's twenty bucks.